#!/usr/bin/env python3
# -*- coding: utf-8 -*-

class Student(object):
    def __init__(self,name,score):
        self.__name = name
        self.__score = score
    def get_name(self):
        return self.__name
    def get_score(self):
        return self.__score
    def set_score(self,score):
        if 0 <= score <= 100:
            self.__score = score
        else:
            raise ValueError('bad score')

    def get_grade(self):
        if self.__score >= 90:
            return 'A'
        elif self.__score > 60:
            return 'B'
        else:
            return 'C'

wkx = Student('Wangkaixuan',100)
print('wkx.get_name=',wkx.get_name())
print('wkx.get_score=',wkx.get_score())
wkx.set_score(61)
print('wkx.get_score=',wkx.get_score())
